macOS notes.

Author: thomthom

macOS.md

@@ -0,0 +1,36 @@
+# macOS Notes
+
+## Useful commands
+
+### Check the architecture of a binary
+
+```
+$ file SUEX_HelloWorld.bundle 
+SUEX_HelloWorld.bundle: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit bundle x86_64] [arm64:Mach-O 64-bit bundle arm64]
+SUEX_HelloWorld.bundle (for architecture x86_64):	Mach-O 64-bit bundle x86_64
+SUEX_HelloWorld.bundle (for architecture arm64):	Mach-O 64-bit bundle arm64
+```
+
+### Check the deployment target
+
+It appear that x86_64 and arm64 binaries doesn't report the same way.
+
+```
+$ otool -arch x86_64 -l SUEX_HelloWorld.bundle | grep -A 5 LC_VERSION_MIN_MACOSX
+      cmd LC_VERSION_MIN_MACOSX
+  cmdsize 16
+  version 10.13
+      sdk 11.3
+Load command 8
+      cmd LC_SOURCE_VERSION
+```
+
+```
+$ otool -arch arm64 -l SUEX_HelloWorld.bundle | grep -A 5 LC_BUILD_VERSION
+      cmd LC_BUILD_VERSION
+  cmdsize 32
+ platform 1
+    minos 11.0
+      sdk 11.3
+   ntools 1
+```